Stainless steel production was originally carried out in electric arc furnaces (EAF) but due to the impossibility to obtain a good and fast mixing of the melt and to the problems associated to get good reducing conditions after the oxidizing period, the added oxygen process (AOD) process was designed for a more economical production. In this process there still exist the problems associated with obtaining good reducing conditions and the bottom blowing of oxygen, plus argon in a technological aspect because of the high wearing rate produced in the AOD lining by oxygen tuyere blowing. Another drawback of the stainless steel production route is the inability of the AOD vessel to maintain a desired temperature in the melt: All energy available comes only from enthalpy delivered during the oxidizing period and the final reducing period is then limited in operations to be done because of melt cooling.
It is therefore an object of the present invention to provide a stainless steel production method in EAF without using the AOD process and having the ability to produce a good and fast melt mixing by bottom blowing a stirring gas.
Another object of the present invention is to provide a stainless steel production route in EAF without using the AOD process and having the ability to reinforce the oxidizing or reducing conditions by natural gas bottom blowing and the possibility to maintain the desired temperature by the electric arc operation.